RF Current Profile - very long RX peaks & Adv Standby?

I am trying to measure and characterize expected battery lifetime of my design. I've noticed that as the effective Connection Interval goes up, so does the Rx current peak duration. At a 1.8sec connection interval, the RX duration is over 600usec (sometimes up to 1100usec!) . This is very power consuming. This is during an idle connection when no data should be exchanged. I am connected to the a PCA10000 acting as the central. Is this around expected behaviour during slow connection parameters?

Also in my measurements it seems the chip goes to stand-by for about 200usec between Advertising Peaks (after Rx post processing, before next Radio Start.) This is contrary to the profile shown in the S110 documentation. Can anyone comment? Thanks